Variable reactive coil.



PATENTED OCT. 22, 1907.

R. E. BARKER. VARIABLE REAGTIVE COIL.

APPLIOATION'IILED JAK23, 1907.

Inventor,

Ral ph E Barker; W

Witnesses:

MM 5 M UNITED STATES PATENT OFFICE.

; RALPH EJ ARKERQOF LYNN. MASSACHUSETTS. .lssroxon TO GENERAL ELECTRIC "COMPANY, A CORPORATION or NEW YORK.

VARIABLE REACTIVE COIL.

Specification of Letters Patent.

Patented Oct. 22, 1907.

Application filed January 23,1907. Serial No. 353,627.

To all/idiom it may concern:

2 .Be it known that I, RALPH E. BARKER, a citiz'en;ot

' which the following is a specification.

fregulating the voltagesupply to alternating-current dc My invention relates to coils of variable reactance for vices-as for instance, to small altcrnating-current niotors Such coils have been made heretofore with opencircuited magnetic cores, but such a constructionis objc'ctionable, since in operation it is ordinarily noisy. be-

cause of the air-gap. Y Z my invention I obtain with a closec'l-circuit core, I

which is noiseless, the same results that have been obftaine'dfheretofore with open-circuit cores. I secure this result-by arranging the core with a closed magnetic circuit, but with varying cross-section; a portion of the core. being arranged to be highlvsaturated by normal currenflflow through the coil. Bv shifting the coil from the saturated to an unsaturated portion of the tore, the reactance. of the; coil ismade to vary widely.

v My invention will-best be understood bvrefercnce'to the accompanving dra'v vings, in which i I J Figure 1 shows a side elevation of a reactive coil arranged inaccordance witlrmy invention; Fig. 2 shows a plan view-oi the same; and I" ig. 3 is a diagram of connections v V ln-t'h'e drawings, A represents-a suitable base, on which the coil B is firmly mounted.

C represents a laminated circular core. which is interlinked with the coil, and which has a circular opening eccentric'with respect'to the peripheryof the core, as is clearly shown in Fig. 2; .With this arrangement the 'cr -section of the core varies, and the core proportioned at its point of smallest cross section to be highly saturated by-thcfcurrent' in the coil B. I'The' core I. is

riveted to a suitable supportl) carried by the controlling lever E, which ismounted on the pivot e, with-itsaxis concentric with the. sectional opening in the core.

By rotating the lever E on it's pivot, the core C is rotated around theside or the coil which it incloscs and the cross-section of the portion of the core i nclosed by .the coil is' varied. A clampin -screw'F is provided on the lever E, and travels in the semi-circular slotf in the base A. By means of this screw and slot 21 'core may be clamped in any position of the core.

When the core is in the position shown in F ig's. 1 and of the coil is greatly increased.

In Fig. 3 I have shown the coil connected for'controlling thevoltage supplied to a small induction motor. Inthis figure G represents a source of alternating current,- H a step-down transformer. I the main winding ot the motor. and J a starting winding adapted to be cut out of jcircuit by the switch K. The motor windings aremerely indicated diagrammatically, since the construction and connections of the motor form no part of my invention. i I

What I claim as new and desire to'secure by Letters Patent of the I'nited States, is: i I

1 A'variahle reactive coll comprising a core. forming a closed magnetic circuit of varying cross-section and a winding on said core. the core and winding being" relatively adjustable. 7 p

g. A variable reactive coil comprising a laminated circular. core with a central opening eccentric with respect to the periphery of the core. and a winding interlinked wvlth said core; the core and winding being relatively adj'ustah'le.

- A variable reactive coil comprising a stationary wind; ing, anda laminated cor'e interlinkedtherewith, said core forming a closed magnetic circuit of varying cross-section and being: adjustable relat'ivel to said winding.

4. A variable reactive coil comprising a stationarvwinth ing and a laminated circular-core having a central opening surrounding said'winding eccentric with respect to the periphery of the core. said core being pi votall v mounted on an axisconcentric with said central opening. p 5. A'variable reactive coil comprising a core forming a closed magnetic'circuit of varying cross-section and a,winding on said core. the core and winding ;being relatively in fixed relative positions.

6. A variable reactive coil comprising a stationary winding and a laminated circular-core having a.central opening surrounding said winding, eccentric-.with respect to the periphery of the core. said core heingpivotally mounted on an axis concentric with said central opening.- and adjustable. and means for cla'rirpingj'fhe coreQand winding clamping means for said core. I v v In witness whereof. I have hereunto set my hand this twenty-first day of January. 1907.

Y RALPH n. BARKER. Witnesses:

Jon) A. McMaxL's, Jr., PHILIP F. I'IAKRIX'GTON. 

